A domain-specific 50-kilodalton structural protein of the acrosomal matrix is processed and released during the acrosome reaction in the guinea pig.
A domain-specific 50-kilodalton structural protein of the acrosomal matrix is processed and released during the acrosome reaction in the guinea pig.
复制标题
顶体基质的域特异性 50 千道尔顿结构蛋白在豚鼠的顶体反应过程中被加工和释放。
DOI：
10.1095/biolreprod51.1.1
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发表时间：
1994
影响因子：
3.6
通讯作者：
Olson,GE
中科院分区：
文献类型：
--
作者：
Westbrook-Case,VA;Winfrey,VP;Olson,GE
精子顶体含有多种水解酶，在顶体反应期间表现出差异释放。水解酶和顶体基质之间的相互作用，以及它们的化学独特的基质域的区室化可能代表实现这种有序释放的机制。本研究的特点是顶体基质蛋白，仅限于最腹侧区域的顶段豚鼠附睾精子。多克隆抗血清，对SDS-PAGE纯化的顶端节蛋白制备，承认一个50 kDa的带，称为AM 50，在Western印迹。天然AM 50对溶解有抗性。然而，在顶体反应期间，AM 50转化为42-43-kDa的双联体蛋白（AM 50 AR）并释放到孵育培养基中。AM 50和AM 50 AR不被豚鼠顶体蛋白原的抗血清识别，并且在明胶分解SDS-PAGE测定中不显示蛋白酶活性。然而，AM 50 AR结合顶部-氨基苯甲脒亲和柱，表明它可能在顶体反应后仍然与蛋白酶结合。光镜和电镜免疫细胞化学证实AM 50仅定位于顶体顶段的腹侧。
The sperm acrosome contains a variety of hydrolytic enzymes that exhibit differential release during the acrosome reaction. The interaction between hydrolases and the acrosomal matrix, and their compartmentalization into chemically unique matrix domains may represent mechanisms by which this ordered release is achieved. This study characterizes an acrosomal matrix protein that is restricted to the ventral-most region of the apical segment of guinea pig cauda epididymal spermatozoa. Polyclonal antiserum, prepared against an SDS-PAGE-purified apical segment protein, recognized a 50-kDa band, termed AM50, on Western blots. Native AM50 is resistant to solubilization. However, during the acrosome reaction, AM50 is converted into a 42–43-kDa doublet protein (AM50AR) and released into the incubation medium. AM50 and AM50ARare not recognized by antiserum to guinea pig proacrosin and do not exhibit protease activity in a gelatinolytic SDS-PAGE assay. However, AM50AR does bind top-aminobenzamidine affinity columns, suggesting that it may remain associated with proteases after the acrosome reaction. Light and electron microscopic immunocytochemistry established that AM50 was exclusively localized to the ventral aspect of the apical segment of the acrosome.